The present invention relates to a method of preparing immunoglobulin (IgG) suitable for intravenous administration. More particularly, the present invention relates to a method of preparing immunoglobulin not containing aggregates of immunoglobulin.
In the present invention, immunoglobulin in powder form, which is referred to as Cohn Plasma Fraction II, is employed as a starting material. Said Cohn Plasma Fraction II (hereinafter is referred to as Cohn Fraction II in short) is obtained by the so-called Cohn Method 9 described in J. Am. Chem. Soc. 71, 541-550 (1949).
Immunoglobulin (IgG) is widely used as a therapeutic agent, and generally, immunoglobulin is administrated by intravenous injection. However, certain impurities such as aggregates of immunoglobulin occasionally contained in immunoglobulin products render the administration of such immunoglobulin by intravenous injection hazardous.
Various methods for the production or the purification of immunoglobulin have been disclosed in the literatures, for instance, U.S. Pat. Nos. 3,415,804, 3,763,135 and 4,093,606, and British Pat. No. 1,372,953.
It is an object of this invention to provide a method of preparing immunoglobulin (IgG) in high purity and suitable for intravenous administration from Cohn Fraction II under conditions different from those disclosed in the specifications of the patents mentioned above.